Save config file as JSON instead of proprietary binary format

Should BNRBot save its config file as a JSON file instead of its own proprietary binary format like it does now?

There are several advantages to this:
- Easy to modify outside of BNRBot
- Easy to add onto with new features or bugfixes

But there's also disadvantages:
- More fragile to user error
- Realbasic's native `JSONItem` class is hard to work with
